1. Field of the Invention
The present invention relates to a heat module. In particular, the present invention relates to a heat module installed in an electronic device, such as, for example, a personal computer (PC).
2. Description of the Related Art
Small and high-performance electronic devices, such as, for example, notebook PCs, produce a large amount of heat at CPUs and the like inside cases thereof. This makes it important to take measures against the heat. One common measure against the heat is to install blower fans inside the cases to discharge the heat. In a common heat module in which a heat source and a heat sink are arranged to be away from each other, the heat source and the heat sink are connected to each other through a heat pipe. Meanwhile, in recent years, electronic devices, such as the notebook PCs, have been becoming thinner and thinner, and there has been a demand for a reduction in the thickness of heat modules. In a heat module, a heat receiving sheet is arranged between the heat source and the heat pipe, and the heat receiving sheet is arranged to axially overlap with the heat pipe. In addition, the heat pipe is arranged to axially overlap with a fan including the heat sink. Thus, to reduce the thickness of the heat module, it is essential to reduce the thickness of the heat pipe. The heat pipe has a cavity inside it, and a working fluid is arranged in the cavity. The working fluid receives heat from the heat source at one end of the heat pipe, and is vaporized. A vaporized portion of the working fluid spreads inside the heat pipe while traveling toward an opposite end of the heat pipe, and is condensed due to increased pressure to dissipate heat. Further, the heat sink is arranged at the opposite end of the heat pipe to facilitate dissipation of heat of the vaporized portion of the working fluid. The portion of the working fluid which has dissipated heat near the heat sink needs to return toward the heat source to continue to dissipate heat. Thus, a capillary structure through which the working fluid is able to travel by capillary action is arranged inside the heat pipe. Due to a reduction in the thickness of the heat pipe, the capillary structure may become deformed to impede travel of the working fluid.
Thus, a variety of heat pipes in which travel of the working fluid is not impeded by a deformation of the capillary structure have been devised. JP-A 2000-074579, for example, discloses a heat pipe including a container having a cavity with a flat cross section, a plate including a recessed portion and inserted in the container, and a wick inserted in the recessed portion of the plate.
In the heat pipe as disclosed in JP-A 2000-074579, the container of the heat pipe can be flattened, but the thickness of the heat pipe can be reduced only to a limited extent because the plate is arranged inside the container. The plate is arranged to position the wick inside the container, and the container cannot be flattened to such an extent that the plate is deformed.